Sofa



FIG. 1 is a front perspective view of a sofa showing our design;

FIG. 2 is a front and side perspective view thereof;

FIG. 3 is a rear and side perspective view thereof; and

FIG. 4 is a rear perspective view thereof.

The side of the sofa not shown in FIGS. 2 and 3 is like the side shown. 

The ornamental design for a sofa, as shown and described. 